Withdrawal of Primary investigators

The purpose of this study is to determine the differences in oxygenation and decarboxylation between two weaning processes.

First, during controlled mechanical ventilation all patients will be ventilated for 5 minutes with 100% oxygen. After 5 minutes an PaO2/FiO2 will be calculated and compared with a PaO2/FiO2 during ventilation with FiO2 - 30%.

The patients will be divided in two sections: Section A are the patients with less than 24 hours mechanical ventilation until weaning start. Section B are the patients with more than 24 hours until weaning start.

The patients in every section will be further divided in two groups. Group 1 will be weaned starting with a PEEP equal with P mean during BiPAP, Group 2 will be weaned starting with a PEEP equal with PEEP during BiPAP.

Further, the weaning will be conducted after an known algorithm. The differences in the oxygenation and decarboxylation will be measured after 30 and 120 Minutes for Group A and after 30, 120, 240, 360 Minutes for Group B.

Inclusion Criteria:

• All Patients that are mechanical ventilated on the intensive care unit.

Exclusion Criteria:

• Patients under 18 years of age
• Patients that where in an other study in the last 30 days
• Patients that are enrolled in other studies
• Pregnant woman
• Nursing mothers
• Existing severe Lung disease
• Existing COPD Gold IV